The present invention relates to a water mist cooling system having significant advantages over prior art water mist cooling systems.
Water mist cooling systems have been in use for a number of years, and are especially used in areas having a hot, dry climate, e.g., the southwestern United States. Water mist cooling systems are also used in hot, humid areas where such systems are installed on fans to aid evaporation.
Mist cooling or flash evaporative cooling (FEC) is a rapidly growing market. There are a large number of suppliers to this industry, and ease of entry into the business is one of the reasons for said large number of suppliers. Unfortunately (for the customers/users of such systems) the prior art systems have a serious shortcoming, i.e., short duration of effective cooling followed by a requirement for maintenance and repair, as will be explained below. A typical prior art system of the type presently being offered by such suppliers is illustrated in FIG. 1, where tap water flows through an optional pre-filter (for removing suspended solids in the tap water) and thence, optionally, to a pump and a regulator R, and thence to a series of nozzles N connected serially together.
Some of the prior art systems merely operate with tap water pressure, i.e., eliminating the illustrated pump and regulator; these systems are especially unsatisfactory, since tap water pressure is typically relatively low. One problem with tap water pressure type systems is that the relatively low pressure means large droplet size. Instead of evaporating, the large droplets provide a shower effect below the nozzles. Even the systems using a pump, so as to operate at a higher water pressure, are not satisfactory as will be explained.
As indicated above, misting is used in hot, dry areas, and water quality in such arid regions is almost always very poor, i.e., the water has a very high level of total dissolved solids (TDS), usually expressed in parts per million (PPM). The nozzle orifices are very small, e.g., 0.001xe2x80x3 to 010xe2x80x3. Thus, when such prior art systems are used, the high mineral content of the water in the arid regions very rapidly clogs the small misting nozzles. To further explain the problem, during periods of non-use, the high mineral content water leaves a scale similar to that left in a coffee pot. The scale breaks off and becomes the sand which clogs the nozzles. Clogged nozzles have a dual negative effect. First, they do not mist, or mist improperly; and second, by not flowing, they cause excessive backpressure to the pumping system, causing premature pumping system failure. Thus, clogged nozzles disable the entire mist cooling system. Another serious problem is the pumps and pumping systems pumping the poor quality water have dramatically shorter lives; the dissolved solids and chlorine in the tap water attack moving and non-moving pump parts.
The present invention provides a mist cooling system wherein the tap water is first processed by a reverse osmosis apparatus to produce pure water, the output of which is connected to a pump which is adapted, when actuated, to pump pure water from outlet means thereof at a preselected pressure. The system further comprises a plurality of misting nozzles serially connected by hollow tubing means to form a line having two ends, the first of said two ends being connected to said outlet means of said pump, whereby pure water is pumped by said pump through said hollow tubing means to said misting nozzles and thence through said nozzles to the atmosphere. The pump is controlled whereby pure water is pumped by said pump at a preselected pressure through said hollow tubing means to said misting nozzles and thence exiting said nozzles as pure water mist to the atmosphere to provide the cooling.
Applicant""s reverse osmosis type pure mist cooling system solves the most objectionable problems with current technology misting systems. More specifically, because of the solvent nature of pure water, the system is continuously cleaned and flushed of impurities. The nozzles do not plug up; instead, the pure water keeps the orifices at the proper factory specification. Not only does the pure water eliminate maintenance of the system, it also dramatically extends the life of the pumping system. No longer do pumps become ruined or disabled by bad water attacking the moving and non-moving parts. Another advantage of the invention is that the pure water misting will not cause xe2x80x9cwater spotsxe2x80x9d on mirrors or other flat shiny surfaces; this advantage is applicable to misting systems used, for example, in the produce department of a food market.
In a preferred embodiment of the invention, a water pressure regulator is located at the very end of the tubing; this arrangement has advantages separate and distinct from the use of the reverse osmosis pure water, and is the subject matter of a co-pending application of the applicant.